The presence of refractory wake impairments in many individuals with severe sleep apnea led us to hypothesize that the hypoxia/ reoxygenation events in sleep apnea permanently damage wake-active neurons. We now confirm that long-term exposure to hypoxia/ reoxygenation in adult mice results in irreversible wake impairments. Functionality and injury were next assessed in major wake-active neural groups. Hypoxia/reoxygenation exposure for 8 weeks resulted in vacuolization in the perikarya and dendrites and markedly impaired c-fos activation response to enforced wakefulness in both noradrenergic locus ceruleus and dopaminergic ventral periaqueductal gray wake neurons. In contrast, cholinergic, histaminergic, orexinergic, and serotonergic wake neurons appeared unperturbed. Six month exposure to hypoxia/reoxygenation resulted in a 40% loss of catecholaminergic wake neurons. Having previously identified NADPH oxidase as a major contributor to wake impairments in hypoxia/reoxygenation, the role of NADPH oxidase in catecholaminergic vulnerability was next addressed. NADPH oxidase catalytic and cytosolic subunits were evident in catecholaminergic wake neurons, where hypoxia/reoxygenation resulted in translocation of p67 phox to mitochondria, endoplasmic reticulum, and membranes. Treatment with a NADPH oxidase inhibitor, apocynin, throughout hypoxia/reoxygenation exposures conferred protection of catecholaminergic neurons. Collectively, these data show that select wake neurons, specifically the two catecholaminergic groups, can be rendered persistently impaired after long-term exposure to hypoxia/reoxygenation, modeling sleep apnea; wake impairments are irreversible; catecholaminergic neurons are lost; and neuronal NADPH oxidase contributes to this injury. It is anticipated that severe obstructive sleep apnea in humans destroys catecholaminergic wake neurons.
Background From February 21, the day of hospitalisation in ICU of the first diagnosed case of Covid-19, the social situation and the hospitals' organisation throughout Italy dramatically changed. Methods The CIO (Club Italiano dell'Osteosintesi) is an Italian society devoted to the study of traumatology that counts members spread in public and private hospitals throughout the country. Fifteen members of the CIO, Chairmen of 15 Orthopaedic and Trauma Units of level 1 or 2 trauma centres in Italy, have been involved in the study. They were asked to record data about surgical, outpatients clinics and ER activity from the 23rd of February to the 4th of April 2020. The data collected were compared with the data of the same timeframe of the previous year (2019). Results Comparing with last year, overall outpatient activity reduced up to 75%, overall Emergency Room (ER) trauma consultations up to 71%, elective surgical activity reduced up to 100% within two weeks and trauma surgery excluding femoral neck fractures up to 50%. The surgical treatment of femoral neck fractures showed a stable reduction from 15 to 20% without a significant variation during the timeframe. Conclusions Covid-19 outbreak showed a tremendous impact on all orthopaedic trauma activities throughout the country except for the surgical treatment of femoral neck fractures, which, although reduced, did not change in percentage within the analysed timeframe.
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